In Multiple Sclerosis (MS) gait disorders represent one of the most disabling aspect that strongly influence patient quality of life. The improvement of walking ability is a primary goal for rehabilitation treatment. Current promising rehabilitative approaches for neurological disorders are based on the concept of the task-specific repetitive training. Hence, the interest in automated robotic devices that allow this typology of treatment for gait training. However, studies on the effectiveness of such methodologies are still poorly numerous in terms of functional improvement in MS patients. The aim of this controlled cross-over study is to evaluate the effectiveness of a Lokomat gait training in patients affected by Multiple Sclerosis in comparison to a ground conventional gait training.

In Multiple Sclerosis (MS), the highly variable distribution of demyelinization areas and axonal loss in the Central Nervous System can lead to very complex and unpredictable neurological deficits and clinical patterns. Gait disorders as reduced speed and stride length, gait asymmetry, increased muscular energy expenditure, balance deficit and increased risk of falling, represent one of the most disabling aspect. These motor problems strongly influence the level of independence that a person affected by MS is able to achieve, resulting in severe negative impact on quality of life. Therefore, the improvement of walking ability is a primary goal for rehabilitation treatment. Many studies demonstrated that a conventional rehabilitation treatment based on physiotherapy could be effective in increasing muscle strength and motor function, improving gait and mobility abilities, reducing fatigue and risk of falls, leading finally to an overall increase of patient autonomy. According to the most recent neurophysiological concepts based on neural plasticity, in recent years the rehabilitative approaches that seem to be more effective in improving functional performance are based on the concept of the task-specific repetitive training. As in the case of the constraint induced movement therapy (CIMT) for upper limb rehabilitation and the body weight support treadmill training (BWSTT) for the lower, the factors that appear to positively affect patient outcome are the intensity, precocity, repeatability, specificity in a training that incorporates high numbers of repetitions of task-oriented practice. Hence, the interest in automated robotic devices for gait training for MS patients has grown. With their consistent, symmetrical lower-limb trajectories, robotic devices provide many of the proprioceptive inputs that may increase cortical activation and stimulation of Central Pattern Generator (CGPs) in order to improve motor function. The use of robot-assisted-gait-training (RAGT) allows: repetition of specific and stereotyped movements in order to acquire a correct and reproducible gait pattern in conditions of balance and symmetry, early start of treatment using the activity with body weight support, safeguard of the patient with reduction of fear of falling, in order to increase the quantity and quality of the performed exercise while minimizing the intervention of a therapist. However, studies on the effectiveness of such methodologies are still poorly numerous in terms of functional improvement in patients with MS. The aim of this controlled cross-over study is to evaluate the effectiveness of a robot-driven gait orthosis (Lokomat - Hocoma, Inc., Zurich, Switzerland) gait training in patients affected by Multiple Sclerosis in comparison to a ground conventional gait training. The improvement in gait pattern, motor ability and autonomy in the functional activities of daily living will be assessed by using validated clinical and functional scales and quantitative instrumental analysis of gait kinematic parameters

Inclusion Criteria:

• diagnosis of multiple sclerosis according to the McDonald's Criteria in stable phase of disease for at least 3 months.
• ability to walk 25 foot without assistance
• EDSS score between 3.5 and 7

Exclusion Criteria:

• exacerbations of the disease in the last 3 months
• deficits of somatic sensation involving the legs
• other neurological, orthopedic or cardiovascular co-morbility
• severe posture abnormalities
• severe-moderate cognitive impairment (Mini Mental State ≤ 21)
• body weight greater than 135 kg;
• height more than 200 cm;
• limb-length discrepancy greater than 2 cm;
• presence of skin lesions on the trunk, pelvis and lower limbs that could interfere with the placement of the electrodes and straps anchoring the Lokomat.